gpu: nvgpu: Add gk20a_fence type

When moving compression state tracking and compbit management ops to
kernel, we need to attach a fence to dma-buf metadata, along with the
compbit state.

To make in-kernel fence management easier, introduce a new gk20a_fence
abstraction. A gk20a_fence may be backed by a semaphore or a syncpoint
(id, value) pair. If the kernel is configured with CONFIG_SYNC, it will
also contain a sync_fence. The gk20a_fence can easily be converted back
to a syncpoint (id, value) parir or sync FD when we need to return it to
user space.

Change gk20a_submit_channel_gpfifo to return a gk20a_fence instead of
nvhost_fence. This is to facilitate work submission initiated from
kernel.

Bug 1509620

Change-Id: I6154764a279dba83f5e91ba9e0cb5e227ca08e1b
Signed-off-by: Lauri Peltonen <lpeltonen@nvidia.com>
Reviewed-on: http://git-master/r/439846
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
Tested-by: Terje Bergstrom <tbergstrom@nvidia.com>

1 files changed, 4 insertions, 13 deletions

diff --git a/drivers/gpu/nvgpu/gk20a/sync_gk20a.c b/drivers/gpu/nvgpu/gk20a/sync_gk20a.c
index 1f2eae1a..da9a0f5e 100644
--- a/drivers/gpu/nvgpu/gk20a/sync_gk20a.c
+++ b/drivers/gpu/nvgpu/gk20a/sync_gk20a.c
@@ -371,12 +371,11 @@ struct sync_timeline *gk20a_sync_timeline_create(
         return &obj->obj;
 }
 
-int gk20a_sync_fence_create(struct sync_timeline *obj,
+struct sync_fence *gk20a_sync_fence_create(struct sync_timeline *obj,
                 struct gk20a_semaphore *sema,
                 struct sync_fence *dependency,
                 const char *fmt, ...)
 {
-        int fd;
         char name[30];
         va_list args;
         struct sync_pt *pt;
@@ -385,7 +384,7 @@ int gk20a_sync_fence_create(struct sync_timeline *obj,
 
         pt = gk20a_sync_pt_create_inst(timeline, sema, dependency);
         if (pt == NULL)
-                return -ENOMEM;
+                return NULL;
 
         va_start(args, fmt);
         vsnprintf(name, sizeof(name), fmt, args);
@@ -394,15 +393,7 @@ int gk20a_sync_fence_create(struct sync_timeline *obj,
         fence = sync_fence_create(name, pt);
         if (fence == NULL) {
                 sync_pt_free(pt);
-                return -ENOMEM;
-        }
-
-        fd = get_unused_fd();
-        if (fd < 0) {
-                sync_fence_put(fence);
-                return fd;
+                return NULL;
         }
-
-        sync_fence_install(fence, fd);
-        return fd;
+        return fence;
 }